


Just Add Water

by croiagusanam



Category: Percy Jackson and the Olympians & Related Fandoms - All Media Types, Percy Jackson and the Olympians - Rick Riordan, The Heroes of Olympus - Rick Riordan
Genre: F/M, Fluff, Mention of Pallas, Mermaid Tails, Olivekinesis, Parenting Advice, Percy is a good dad, Soft Triton, percababies, technically not a h2o au
Language: English
Status: Completed
Published: 2020-08-20
Updated: 2020-09-16
Packaged: 2021-03-06 19:20:16
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,250
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26014018
Author URL: https://archiveofourown.org/users/croiagusanam/pseuds/croiagusanam
Summary: Percy knew that he should probably wake Annabeth. He’d promised to wake her in case of emergencies, and this definitely felt like it could be construed as an emergency. Then again, he thought she desperately needed the sleep. Plus, his paternity leave was nearly over, and he wanted her to have as easy a time as possible before he had to go back to work. And really, how big of a deal could their son becoming a merman be?
Relationships: Annabeth Chase/Percy Jackson, Juniper/Grover Underwood
Comments: 15
Kudos: 229





	1. Fatherhood and Fishy Tails

Percy knew that he should probably wake Annabeth. He’d promised to wake her in case of emergencies, and this definitely felt like it could be construed as an emergency. Then again, he thought she desperately needed the sleep. Plus, his paternity leave was nearly over, and he wanted her to have as easy a time as possible before he had to go back to work. And really, how big of a deal could their son becoming a merman be?

The whole ordeal had started one Friday evening when Percy had arrived home to Annabeth clutching a positive pregnancy test. While they hadn’t been trying for a child per se, they had decided long beforehand that children were in their future. And hey, they both had stable jobs with plenty of parental leave, and Annabeth’s firm had a great daycare option for when they both wanted to go back to work. What’s the worst that could happen?

The stress of a demigod pregnancy had arrived not long after. Percy had awoken in the middle of the night to a sobbing wife clutching him and begging him to ‘wield the axe if it comes to that.’ After he managed to coax the nightmare she had of Athena’s birth out of her, he had promised to be as gentle as possible with any axe he had to use. They had laughed about it over breakfast the next morning. A few days later he had his own nightmare, involving all the relatives on his godly side. Percy had shaken her awake, asking if she would still love him if their child was part horse or had wings. Annabeth had assured him that she would, and that they’d just have to invest in an extra strength harness and kiddy leash to make sure they didn’t fly off.

Annabeth’s twelve week scan had cleared all that stress up. Their son was decidedly not situated in her head, and was perfectly healthy with no extra appendages. Telling everyone had been easy after that. Sally and Paul had teared up (and so had Piper, not that she’d ever admit to it.) Even Frederick had managed to tear his focus away from work to sound proud. Honestly, it had been so easy Percy should have been expecting what had come next. He’d been cooking up a huge batch of beetroot burgers to freeze (it was all Annabeth could stomach) when he was interrupted by a knock on the door. He barely had time to register the visitors before Aphrodite was rushing in with congratulations and kisses on both cheeks - followed by Athena and Hera, both looking far more uncomfortable with the situation than the love goddess. Dazed, Percy had welcomed them in, then mused aloud about how long it must have been since they had been alone with a mortal. Aphrodite had murmured something about a golden apple and the other goddesses had glared with such venom that Percy had almost been prepared to lose their apartment to some sort of divine battle. Thankfully at that point Annabeth had come in the door, breaking the tension.

What had followed was an incredibly awkward impromptu dinner party. Aphrodite had winked and said she was glad that her blessing had worked (Percy was sure even Athena had flushed a little at that), before Hera had declared that she hoped all of their issues were behind them, allowing her to bless the pregnancy and birth. Athena simply stated that she approved of the match. Percy had said little more than two words the whole night but noted rather smugly that the goddesses had all left an empty plate behind (despite never seeming to eat) as he did the washing up while Annabeth had told him of how Artemis had approached her with a similar (though far less cold) blessing to Hera’s. For better or worse, this baby had the full attention of Olympus.

The last major issue had been navigating the baby shower. Demigods and the Hunters of Artemis mixing with their mortal friends had been bad enough, before a truck full to the brim of anything a baby could need arrived. Seemingly Queen Hylla had heard about the event and had forwarded a directory to the Empire State Building. Annabeth had quickly explained to the mortals that the ‘Greek’ side of the family was very generous, and had a tradition of making up for not being able to attend events in the US. Percy was pretty sure the cost of a storage unit would offset the benefit of never having to buy diapers, but he supposed it was the gesture that counted. Charlie had been born shortly after, and the next four months had passed uneventfully. Until now, that is.

Percy looks down at Charlie, giggling and splashing his iridescent tail about in the water and makes up his mind. He turns on the torch on his phone, and grabs the shower head and turns it on to make a mist, flipping a drachma into it.

“Oh Iris, goddess of the rainbow, please accept my offering. Show me Grover Underwood.” The rainbow wavers and then connects, treating him to an image of Grover sitting on a beach, watching from a distance as Juniper and their daughter run about.

Grover turns and breaks into a smile. “Hey Percy! I was just thinking about giving you a call - got a sudden sense of distress and was hoping it was you and not the enchilada’s Don brought with him when he came to visit.”

“Grover, I was just thinking about when Theodora was going through her transforming stage. Y’know, when she kept jumping between baby and sapling at a moment's notice. How uh, how long did that last?”

“About a month or so I think? It’s pretty common for young nature spirits to flip back and forth before they learn to control it. What’s so important about it you had to call me?” His eyes narrow in suspicion. “What’s going on, Percy?”

“Lets say, hypothetically, I was giving Charlie a bath,” Percy says, voice neutral “and then hypothetically, I were to look away for one second only for his legs to be replaced with a fishtail. How long would it take for said tail to go away?”

Grover looks stumped. “I uh … I have honestly no idea. What does Annabeth think?” His eyes widen at Percy’s sheepish face. “Dude, you called me before you told her? She’s gonna kill you!” He sighs. “Look, maybe you should ask your brother. I don’t have any experience with watery stuff”

Percy snorts. “I love Tyson, but his last piece of parenting advice was-”

“Not Tyson. Triton. I know you guys haven’t always gotten along, but he would know best about grandchildren of Poseidon given he’s had a few. Oh gotta go, Juniper and Dora are coming back! Good luck, and tell Annabeth-”

His voice is cut off as Percy waves his hand through the rainbow. Grover was probably right, even though Percy can count the number of times he’s spoken to Triton on one hand. If nothing else, Charlie would need somewhere to live if he was permanently stuck like this.

“Oh Iris, goddess of the rainbow, please accept my offering. Show me Triton, Prince of Atlantis.”

The image shimmers and reforms to show Triton seated in a throne of dark stone, inlaid with pearls. He had been speaking with a dolphin, but turns his full attention to the message.

“Perseus. To what do I owe this honour?”

Percy can’t decide if there’s a hint of sarcasm in his words but decides to not read deeply into them.

“Lord Triton, it’s great to speak with you again. I - well firstly I wanted to thank you for your gift to Charlie, it’s one of his favorites.” That much was true. The mobile Triton had given them, made from reflective shells and pearls had been one of the few gifts they’d received from the gods that had become a fixture in their home. “I also wanted to ask your advice about something.” Rather than run through an explanation he simply lifts the protesting baby out of the water so that he’s in view of the Iris message.

Triton smiles, a little wistfully. “ I see. Did you perchance attempt to dry him off?” Percy flushes a little at getting such a simple answer, making Triton chuckle. “Don’t worry, little brother. It is nothing too serious. Pallas … well she had the same abilities. In time he will learn to control it, but until then it would be wise to avoid placing him in water around mortals.”

Percy sighs, glad that his undersea boarding school idea could be laid to rest. “Thank you, Triton. It’s a massive relief to know he won’t be part fish forever. Uh, no offense.”

“None taken.” Triton smiles again, but his eyes seem to be tinged with sadness. “Will you do me a favour, Percy? Keep the mobile safe. It was her favourite.”

The connection ends, and Percy sits in the quiet for a moment, before he begins to dry Charlie. Sure enough, the tail disappears and is replaced with legs. Once he’s dressed. Percy carries his son into the bedroom and gives Annabeth a shake. She wakes quickly, bleary eyes settling on them.

“Whasswrong” she mutters, rubbing the sleep out of her eyes

“Nothing, Wise Girl. It's just - did you ever see that Australian mermaid show?”


	2. Olives and Owls

**Summary for the Chapter:**

> Silena was like her mother, they said. No special powers, but likely to be a quick learner as she seemed to constantly be observing anyone who spoke around her, before babbling a fast imitation of speech in response. 
> 
> Of course Percy had been alone with her when she decided to prove them wrong.

**Notes for the Chapter:**

> thank you so much to [Lydia](https://waltstone.tumblr.com/) who proofread this and made some wonderful suggestions! ily <3

Annabeth had been surprisingly calm about the fact that their child could grow a tail at the drop of a hat. In fact, she hadn’t interrupted him once, just fixing him with an intense look. As much as he enjoyed watching her focus, when it was directed at him he always felt as if he knew what it was like to be a mouse caught under the gaze of a hungry bird of prey. Athena sometimes made him feel the same way. Not that he’d ever dare say that out loud. In the end, “I suppose you’ll have to teach him to swim, and I’ll buy him the best poncho I can find tomorrow,” was all that she had said before sitting up and taking the baby from him. “Now Charlie, are you hungry?”

Telling their friends and family had been at least a bit more exciting. Estelle had been a bit put out that they had refused to allow her to bring her ‘mermaid nephew’ to show and tell, but had been placated by the offer of a best aunt award (and a mountain of candy) if she kept quiet about it in front of her school friends, along with being allowed to draw pictures of him. Her teachers had already praised her creative stories about her superhero brother, so hopefully nobody would so much as bat an eye at the drawings. Sally had said almost nothing at all, (once she had finished looking Charlie over from head to toe) apart from a comment about how she was glad that Percy hadn’t been a mermaid himself. The friend side had been slightly more tumultuous, as they had been ribbed endlessly for somehow being unable to have a normal life even after ‘retiring’ from questing. Said jokes only got louder when Charlie’s first word hand turned out to be ‘mama.’ Piper had shouted out something about how apparently adoration of Annabeth and an inability to stop talking about her ran in the men of the family (along with watery weirdness.) Percy held back a comment about the terrors of a toddler with charmspeak. 

Still though, life went on. When Charlie was a year old, Annabeth found herself pregnant again. This second pregnancy was uneventful, no nightmares, no godly dinner parties. Silena was born when Charlie was 18 months old, blonde hair to contrast his black, sharp green eyes against his soft grey ones. They anxiously watched as she grew for any sign that she had abilities like her brother, but as they approached the 7 month mark it seemed like they were in the clear. Silena was like her mother, they said. No special powers, but likely to be a quick learner as she seemed to constantly be observing anyone who spoke around her, before babbling a fast imitation of speech in response. 

Of course Percy had been alone with her when she decided to prove them wrong. 

-

Annabeth had taken Charlie to do the grocery shopping while he stayed home and cooked dinner. He had strapped Silena into her high chair and set about shaping the pizza dough he had made the night before. Silena giggles as she reaches out towards the dough while it spins around in the air. That done, he spreads out the sauce and cheese before sprinkling the toppings over: ham and pineapple on his half, olives and red onion on hers, a mildly horrifying mix of all four on the mini pizza he’d made for Charlie. He tosses a few olives from the jar into his mouth. He’d gone this long pretending he hated them in front of Annabeth that once he had discovered a taste for them, he had to sneak them to keep up the ruse. (Though she definitely knew why the jars emptied so fast, just like he knew exactly which drawer his razors ‘disappeared’ to when she decided she was tired of him being clean shaven.) Just the spice to add, then. Annabeth liked her pizza with far more of a kick than he did, so that was the last thing he always added. He’d forgotten to take it out of the cabinet, though.

Percy moves away from the table, smiling at Silena as she babbles, waving her spoon at him high from her high chair. He ruffles her hair as he walks past, stepping in behind her to reach up into the cabinet for the pepper flakes. Then he feels something small and slightly damp bounce off of the back of his head. Percy smiles, then spins about as fast as he can. “Caught you, ‘Lena!” he shouts, snorting as her green eyes widen in surprise at him catching her in the act. 

Wait a second. Silena was in her chair. Which was facing  _ away  _ from him, so if Silena was looking at him… Percy hears the jar he was holding clatter to the floor as he grabs the counter to support his buckling legs. He looks down at his feet, taking a steadying breath when another firm object bounces off of his forehead. 

An olive, he realises. It lands on the floor next to the jar of chilli flakes, before starting to lift off the ground. He tracks it as it raises up into the air, before stopping about a foot in front of his daughter's eyes. It then flew at him, bouncing off of his nose this time. Alright, that was the last olive he was taking. Gods knew that he’d been on the receiving end of far too many when he and Annabeth had first moved in together. He stands up, and picks up the jar, edging around the table, watching as her head spun to follow his movement.

“Fuck. Why is it never your mother who discovers the strange stuff?” Percy mutters, before smiling up at his frowning daughter, not wanting to upset her. He replaces the lid on the olive jar. As endearing as it was, he does not need to be interrupted during this phone call. 

Unfortunately, he only gets her voicemail. “Hey ‘Beth, remember when we thought Silena was gonna be the normal kid? Yeah, uh, get home as soon as you can.” He’s about to hang up when he does a double take, cringing at how that sounds and adds “we’re both fine, I’m just a little bit spooked.” Taking a deep breath, he steps up to the table again. If Annabeth is going to be rushing home, the least he can do is have dinner ready for when she arrives.

20 minutes later, Silena is dozing in his arms when he hears the rattle of Annabeth’s keys in the door, and her voice softly calls down the hall. “Perce?”

“In here,” he responds in a similar tone of voice. She walks into the kitchen and sets the grocery bags on the counter. Silena wakes at the noise and extends her hands out to Annabeth, who obliges and holds her close, before fixing her eyes on Percy. 

“Charlie is napping in the stroller, I figured it was better to leave him be if we needed to talk.” Annabeth sighs and plants a kiss onto the top of Silena’s head as the baby nuzzles into her. “So, what fishy weirdness has she picked up? Not a tail, I’m guessing?”

“Not a tail, no. Just watch.” He grabs an olive from the table and tosses it at them. Annabeth’s noise of protest dies in her throat as the fruit stops in midair before flying back across the room to Percy’s waiting hand. He watches her as she processes that for a moment, before she sighs and looks to the ceiling.

“Really, mom? All I get is a quest to the death, but your legacies get fu-” She swallows the swear and glances towards the stroller in the hall. “They get olivekinesis?”

That’s what finally makes Percy smile. “For what it's worth, sweetheart, I think it’s from being a combination legacy of Poseidon and Athena. Controlling stuff from me, and -”

“And olives from me.” She looks at him again, like he’s an equation she can’t quite figure out. “I mean that is weird, but I don’t see why it required an urgent phone call.” 

“That isn’t why.” He took a protesting Silena from Annabeth and stood in the centre of the room. “Ok now, get her attention and walk around me.” Annabeth obliged, picking up Silena’s favourite toy (a clumsily sewn fish that had been a gift from Tyson) and walked around them, cooing and chatting to the baby. Sure enough, Silena’s grumpiness at being passed about quickly faded as her head tracked Annabeth almost the full way around. When Annabeth finished her circuit, she leaned back on the table.

“Huh. I always thought I imagined that. No wonder Travis was scared of me for so long.”

Percy frowns. “What does that mean?” Annabeth smirks in response.

“Travis first came to camp when I was 9 and he was about 10, I think? He and Connor started pranking right away, just small stuff mostly. One winter night I woke up to someone shuffling around in the Athena cabin, and I was meant to be the only year round camper in there at the time. Anyway, I was somehow able to look about without moving, just to catch a terrified looking Travis there, before he sprinted out. I went back to sleep, and woke up assuming it was a dream. Come to think of it though, neither of them tried pranking me in person after that.” She twists her head to either side. “Can’t do it now though, so I guess she’ll grow out of it. Maybe I can use it to get back at Connor for that tarantula…”

Percy snorts a laugh, placing Silena back into her chair. “You should go wake Charlie or he won’t sleep tonight. I’ll get the pizzas out.” He looks back over his shoulder. “Guess you really do take after your mom, huh ‘Lena?”

“Fuck,” says Silena, nodding at him.

Well, maybe she was more like him after all.

**Notes for the Chapter:**

> [follow me on tumblr](https://www.tumblr.com/blog/thatirishmichael) and let me know what you think!

**Author's Note:**

> Felt like writing something soft to distract from the sadness of the transistor au (plus party-ponies discord discussions always make me inspired)


End file.
